TNETV2501INPGF datasheet(45/197 Pages) TI1

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Functional Overview

December 2002 − Revised November 2008

SPRS206K

3.3.2 Host Port Mux

The 5501 Host Port Mux controls the function of 8 data signals (pins HD[7:0]) and 2 control signals (pins HC0

and HC1). The Host Port Mux supports two different modes:

•

8-bit multiplexed mode: The HPI’s 8 data and 2 control signals are routed to their corresponding pins

on the Host Port Mux.

•

Parallel general-purpose I/O mode: All pins on the Host Port Mux are routed to PGPIO. The HPI and

EMIF are disabled.

The mode of the Host Port Mux is determined by the state of the GPIO6 pin at reset. If GPIO6 is low, the pins

of the Host Port Mux will be set to PGPIO. In this mode, the EMIF and the HPI will be disabled. The

Parallel/Host Port Mux Mode bit of the External Bus Control Register will be set to 0 to reflect the PGPIO mode

of the Host Port Mux.

If GPIO6 is high, the HPI will be enabled in 8-bit (multiplexed) mode: pins HD[7:0] are set to HPI.HD[7:0], and

HC0 and HC1 are set to HPI.HAS and HPI.HBIL, respectively. The Parallel/Host Port Mux Mode bit field in

the XBSR will be set to 1 to reflect the HPI multiplexed mode of the Host Port Mux. See Section 3.7, Host-Port

Interface (HPI), for more information on the operation of the HPI in multiplexed mode.

Table 3−5 lists the individual routing of the HPI and PGPIO signals to the Host Port Mux pins.

Table 3−5. TMS320VC5501 Routing of Host Port Mux Signals

PARALLEL/HOST PORT MUX MODE = 0

(PGPIO)

PARALLEL/HOST PORT MUX MODE = 1

(8-BIT HPI MULTIPLEXED)

Data Bus

HD[7:0]

PGPIO[43:36]

HPI.HD[7:0]

Control Bus

HC0

PGPIO44

HPI.HAS

HC1

PGPIO45

HPI.HBIL

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